This invention relates to the field of medical devices, and more particularly to a MRI compatible disposable or reusable cranial drill, a sterile barrier for use with a cranial drills, and methods for their use.
Two issues with a medical device having several internal moving parts and mechanisms are cleaning and sterilization. These are especially troublesome if the device is to be used more for more than one procedure. Without disassembling, cleaning, and then re-assembling the device, it is difficult to do these steps adequately if the cleaning and sterilization steps are done at the hospital. Furthermore, it is difficult to design a device that can withstand the rigors of multiple sterilizations. Thus there is a need for a method and apparatus that can eliminate the need for resterilization.
An endoscope, a long instrument which is inserted in a body through the mouth or anus, is used for viewing internal structures of the body. A long tubular barrier has been used with an endoscope. A barrier for use with an endoscope has no features to accommodate rotating parts. There is a need for an apparatus and method for providing a sterile barrier for a device having rotating parts, such as a drill bit, for example. There is a further need for a method and apparatus that can eliminate the need for resterilization of a device such as a cranial drill or the like.
An additional issue associated with a cranial drill is the determination of a stopping point in the drilling process. It can take a long time to go through the process of drilling a small distance and stopping repeatedly to ascertain whether a necessary or desired depth has been reached. There is a need for an apparatus and method for automatically determining when to stop drilling or when the process is completed.
The present invention provides cranial drills which are reusable or disposable. In one embodiment, the present invention provides a MR compatible cranial drill which is disposable. In one embodiment the present invention provides a MR compatible cranial drill which is reusable. The present invention in another embodiment provides a disposable sterile barrier for use with a cranial drill, which eliminates the need for re-sterilization. The sterile barrier may be used with a disposable cranial drill or a reusable cranial drill. When used with a disposable drill, the disposable drill becomes xe2x80x9cre-sposablexe2x80x9d, i.e., the disposable drill may be used up to about five times and then discarded. When the sterile barrier is used, only the patient contacting portion of the drill, the drill bit, requires resterilization. The drill assembly itself is isolated from the patient with a sterile barrier. The barrier has an aperture that allows the drill bit to pass through the barrier while maintaining a seal around the circumference of the bit. In one embodiment, the barrier comprises a bag made of plastic. The drill assembly does not need to be designed to withstand several sterilizations. The novel aperture of the barrier allows a moving or active component of the drill assembly, i.e. the drill bit, to penetrate through the sterile barrier and function on both sides. In one embodiment, the sterile barrier is provided as a sterile kit in combination with a sterile drill bit pre-mounted in the aperture.
In one embodiment the present invention provides a cranial drill having an adjustable depth stop to allow the user to set a predetermined depth of penetration. The adjustable depth stop in one embodiment includes an adjustable screw. In another embodiment the depth stop includes a spring mounted clip shaped to mate with serrations provided on the exterior of a drill housing. In further embodiments the depth stop includes a push button ratchet or a collet lock.